This invention relates to a compact fluorescent lamp head or fixture, and more particularly to a fluorescent lamp fixture having a domed light reflector with a lamp bulb retained therein by means of a releasably securing and pivoting relamping structure. An elongated lamp bulb unit projects through a side opening transversely into the reflector to a point closely adjacent a generally opposite interior wall portion. In such a fixture it is quite desirable to have the lamp bulb accurately positioned in the dome reflector for optimum light transmission therefrom. When such a fixture is adapted for mounting in a ceiling or wall structure of domestic housing, for example, the dome reflector may occupy a rather large space in order to accomodate a larger lamp bulb, an appropriate lamp bulb base socket therefor, and provision for electrical wiring to be connected to be socket.
Ordinarily, walls and ceilings of domestic housing structures, as well as lighting panels, have a limited depth or thickness dimension to accommodate larger domed reflector fixtures whereas larger domed reflectors faciliate replacement of lamp bulbs, a practice referred to as relamping.
The above and associated relevant problems of limited space have been resolved to some extent by the use of more compact fixtures in which the height of a reflector is reduced by having a lamp bulb which projects into a dome reflector transversely thereto, e.g., along an axis such that the longitudinal axis of the lamp bulb or unit is generally parallel to but spaced from a ceiling or wall in which the lighting fixture may be mounted, or parallel to and spaced from the plane of the open end of the reflector. Such a fixture, or lamp head entails a further problem associated with the need to replace the ordinarily expendable lamp bulbs at periodic intervals.
In a ceiling mounted lighting fixture where an incandescent lamp depends downwardly, a long rod having a lamp bulb grip device at one end is used to reach and engage the lamp bulb for the usual twisting motion to release the lamp bulb, and replacement is accomplished by fitting a new or useable lamp bulb to the engaging device or lamp socket in the fixture. A long rod, grip means as described is not readily adaptable for a transversely mounted lamp bulb as described, and provision is usually made for direct manual replacement from a ladder or appropriate scaffolding. In light fixtures which are portable or multi-directionally adjustable, such as desk, floor, or study lamps, for example, the lamp head is readily accessible or may be adjusted to readily facilitate manual lamp bulb removal and replacement.
As previously described, in many improved and compact designs of light fixtures, larger and longer lamp bulbs are positioned transversely in a domed reflector with the result that the dome configuration imposes a limitation on the useful length of a lamp bulb and the extending end of the lamp bulb lies closely adjacent the interior surface of the reflector. Replacement of most reflector housed transverse lamp bulbs requires a significant movement of the lamp bulb axially along its longitudinal axis to release the lamp bulb from its socket or receptacle connector, and the close proximity of a transverse lamp bulb to the reflector (which is often necessary to obtain maximum light intensity) constitutes a definite hindrance to lamp bulb replacement.
Accordingly in some lighting fixtures, a covered or uncovered aperture is provided in the dome reflector through which relamping is carried out. However, such apertures and covers generate some undesirable interference in the optimum light reflecting characteristics of the reflector. Other solutions to the foregoing problem of relamping a transversely positioned lamp bulb entail the use of a lamp unit which is deeply recessed or mounted in the fixture so that the lamp bulb is effectively released from its socket without the need for an excess axial distance to facilitate manual relamping. Angularly rotatable lamp bulb sockets are also utilized to provide better access to the lamp bulb as well as increased lamp bulb to reflector clearance. Angular rotation mechanisms for lamp sockets have been found to be troublesome because the associated high temperature and temperature fluctuations cause the usual friction stops of the angular motion device to loosen and change the accurate positioning of the lamp bulb in the reflector or grip socket. Also, inadvertent or impulsive rotation of a friction retained socket by grasping and turning the lamp bulb leads to breakage of the lamp bulb at the bulb/base connection. Prior art examples of angularly rotatable lamp units are found in U.S. Pat. Nos. 1,757,345 - Tausig, May, 1930 and 2,816,216 - Dasher, December, 1957.